Numerous systems for catheter delivery of implants have been devised over the years in order to assist medical operators in delivering and positioning implants, for example, occluders, within a patient, preferably in a minimally invasive manner. A problem with many of the known delivery systems is their limited flexibility for positioning or retrieving the implant.
Most implant delivery systems include an elongated catheter that is used to access various passageways inside a patient's body. Often the desired position of the implant may not align with the longitudinal axis of the catheter. Upon release of the implant, the implant may shift position causing possible trauma to the surrounding tissue as the distal end of the catheter springs back to a more relaxed state. Such shifting in the implant position may result in a less desirable medical result (such as device embolization or a residual leak in the case of septal occluders).
Implants may include devices designed for compression into a small size tube or catheter to facilitate their introduction into the vasculature of the patient. The implants are subsequently expandable either to occlude defects or holes in the heart, in the case of intracardiac septal occluders, or to contact the walls of the passageway (e.g., blood vessels), in the case of vena cava filters or stents. Among these devices are septal occluders well-known in the art such as the occluder described in U.S. Pat. No. 5,425,744 issued to Fagan et al. Septal occluders are useful in treating medical conditions such as patent foramen ovale (PFO), which is a persistent, one-way, often flap-like opening in the wall between the right atrium and left atrium of the heart, as well as other congenital and acquired defects in the heart or vasculature.
Various types of attachment mechanisms for delivering and releasing an intracardiac occluder are known in the art such as threaded male and female members as described in U.S. Pat. No. 5,725,552 issued to Kotula et al. or ball-to-ball (or pin-to-pin) attach/release mechanisms, such as the attach/release mechanism illustrated in Transcatheter Therapy in Pediatric Cardiology (1993): 335-348. These systems, however, provide little versatility with respect to positioning the implant and disconnecting the implant from the delivery device.
Accordingly, there is a need to provide a delivery system that is capable of reversibly receiving an implant so as to easily retrieve the implant should it be positioned incorrectly and which also has a flexible attachment system for release of the implant once it is positioned.